Co-salen functionalized on graphene as an efficient heterogeneous catalyst for cyclohexene oxidation

Co-salen functionalized on graphene with an average pore size of 27.7 nm as a heterogeneous catalyst exhibited good catalytic activity and recyclability in cyclohexene oxidation.

Photopolymerization of Cyclohexene Oxide Initiated with Iron-arene Complex

Two iron-arene complex photoinitiators with different substituents in arene ligands were synthesized, their activities in initiating photopolymerization of cyclohexene oxide (CHO) were compared with that of IRGACURE 261, a commercialized photoinitiator from Ciba-Geigy. A higher activity was found when the arene ligand was substituted with a stronger electron donating group. For the system initiated by IRGACURE 261 the concentration of active centers in CHO polymerization was determined and it was found that the concentration is maximum at around 35℃. The post (dark) polymerization was significant, the polymerization yield decreased with the increase of irradiation temperature and increased with the increase of post polymerization temperature. The results are interpreted based on the mechanism proposed by Lohse, et al..

Catalytic oxidation of cyclohexene to cyclohexanone by a triple system in acidic aqueous acetonitrile medium

The catalytic oxidation of cyclohexene to cyclohexanone using Pd(OAc)(2)/HQ/FePc was investigated in an acidic aqueous solution of acetonitrile. The role of each component of this system in the oxidation of cyclohexene was explored by means of UV-VIS, IR, XPS spectroscopy and. cyclic voltammetry, respectively. Based on the experimental results, the mechanism of the oxidation of cyclohexene catalyzed by Pd(OAc)(2)/HQ/FePc was elucidated.

Further study on the synthesis of F-containing porphyrins and their catalytic activity on oxidation of cyclohexene

Reaction of tetrakis(p-allyloxyphenyl)porphyrin and perfluoroalkanesulfonyl bromides gives tetrakis(p-polyfluoroalkoxylphenyl)substituted porphyrins.The yields are over 90%.The synthesis of the metal ion complexes of these F-containing porphyrins is also reported.Preliminary results on the study of the catalytic activity of the manganese(Ⅲ)complexes of various fluorinated porphyrins on oxidation of cyclohexene indicate that the introduction of R_F group into porphyrin contributes to the stability of the catalysts.

ALTERNATING COPOLYMERIZATION OF CYCLOHEXENE OXIDE AND CARBON DIOXIDE UNDER COBALT PORPHYRIN CATALYST

Cobalt porphyrin complexes （TPPConIX） （TPP = 5,10,15,20-tetraphenyl-porphyrin; X = halide） in combination with bis（triphenylphosphine） iminium chloride （PPNC1） were used for the eopolymerization of cyelohexene oxide and CO2. The highest turnover frequency of 67.2 h^-1 was achieved after 13 h at 20℃, and the obtained poly（1,2-cyclohexylene carbonate） （PCHC） showed number average molecular weight （Mn） of 10 × 10^3. Though the obtained PCHC showed atactie structure, the m-centered tetrads content reached 58.1% at CO2 pressure of 1.0 MPa, and decreased to 51.9% at CO2 pressure of 6.0 MPa, indicating that it was inclined to form atactic polymer at high CO2 pressure.

SYNTHESIS AND CHARACTERIZATION OF HIGH MOLECULAR WEIGHT POLY(1,2-PROPYLENE CARBONATE-co-1,2-CYCLOHEXYLENE CARBONATE) USING ZINC COMPLEX CATALYST

Using supported multi-componem zinc dicarboxylate catalyst, poly（1,2-propylene carbonate-co-1,2-cyclohexylene carbonate） （PPCHC） was successfully synthesized from carbon dioxide （CO2） with propylene oxide （PO） and cyclohexene oxide （CHO）. The conversion of epoxides dramatically increased up to 89.7% （yield： 384.2 g of polymer per g of Zn） with increasing reaction temperature from 60℃ to 80℃. The optimized reaction temperature is 80℃. The chemical structure, the molecular weight, as well as thermal and mechanical properties of the resulting terpolymers were investigated extensively. When CHO feed content （mol%） is lower than 10%, the PPCHC terpolymers have number average molecular weight （Ma） ranging from 102 × 10^3 to 202 × 10^3 and molecular weight distribution （MWD） values ranging from 2.8 to 3.5. In contrast to poly（propylene carbonate） （PPC）, the introduction of small amount of CHO leads to increase in the glass transition temperature from 38.0℃ to 42.6℃. Similarly, the mechanical strength of the synthesized terpolymer is greatly enhanced due to the incorporation of CHO. These improvements in mechanical and thermal properties are of importance for the practical application of PPC.